EVOLUTION-MANAGER

Edit File: getElements.S

getElements = function(elementNames) { els = list() startElement = function(node, ...) { if(xmlName(node) %in% elementNames) els[[length(els) + 1]] <<- node node } list(startElement = startElement, els = function() els) } # h = getElements("a") htmlTreeParse("http://www.omegahat.net/RSXML/index.html", handlers = h) links = sapply(h$els(), function(x) xmlGetAttr(x, "href")) # Of course, we could do these two steps in one with a handler # function like # getLinks = function() { links = character() list(a = function(x) links <<- c(links, xmlGetAttr(x, "href")), links = function() links) } # h = getLinks() # htmlTreeParse("http://www.omegahat.net/RSXML/index.html", handlers = h) # h$links() # If we want the nodes, we can use getElements. Otherwise, we # can use a specialize handler that converts the information on the # fly into the data structures we want at the end.